This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. To follow up our results on the phosphorylation of Ace2 by Cbk1, we have begun collaboration with Eric Weiss at Northwestern University. We have assisted them in performing immunoisolations of Protein A- tagged Ace2 for the application of HMS-MS and other studies.